Company Email: February 2010
"We do not use isinglass or any animal product in our brewing process."

Company Email: October 2009
"I am with the Clipper City Brewery home of Heavy Seas. All the beers that we make are vegan. no fish bladders here! That isinglass, besides not being vegan, is just plain 'Eeew'. We are 100% vegan - no animal by products"

UPDATE:
Company Email:
"We don't use any finings to clarify our beers."

Company Email:
"We do not use any animal products in any of our beers."